This invention relates to the inspection of the upper end of casing set in the bottom of a body of water to which riser pipes can be connected which extend to a floating structure.
In recent years there has been attention directed toward many different kinds of floating structures. One system receiving attention for mooring is the so-called Vertically Moored Platform (VMP). A Vertically Moored Platform can be described as a floating marine structure for drilling wells and/or producing hydrocarbons from an underwater formation and anchored by essentially parallel, vertical, and elongated members such as riser pipe. Riser pipes are usually considered to be heavywalled, 18-inch steel pipe. In the preferred form of a Vertically Moored Platform, the riser pipes are without slip joints and provide the only anchoring means for the Vertically Moored Platform. Such a platform is described in several patents, including U.S. Pat. No. 3,648,638, issued Mar. 14, 1972, Kenneth A. Blenkarn, inventor.
In these instances of the Vertically Moored Platform, a plurality of casing is set in a selected pattern in the bottom of the body of water so as to resist any upward force. The upper end of these set casings are provided with connectors which mate with connectors on the lower end of riser pipes which are supported by and lowered from the floating structure. Once the connection is made between the riser pipes and the said casing, the structure is anchored.
Perhaps the closest known prior art is the well-known systems of using x-ray to inspect welds in pipelines.